Counterbalancing mechanism for articulated overhead doors



2 sHEETsL-SHEET 1 D. M. ROBINSON COUNTERBALANCING MECHANISM FOR ARTICULATED OVERHEAD DOORS March 10, 1953 Filed Feb. 18, 1950 DAV/'D MROBINSON March 10, 1953 D. M. ROBINSON COUNTERBALANCING MECHANISM FORARTICULATED OVERHEAD DOORS 2 SHEETS--SHEET 2 Filed Feb. 18, 1950 om Q9wm SQ QQ mm me/wm DAJ/JD MROBJNJON Patented Mar. 10, 1953COUNTERBALANCING MECHANISM FOR ARTICULATED OVERHEAD DOORS David M.Robinson, New Britain, Conn., assigner to The Stanley Works, NewBritain, Conn., a corporation of Connecticut Application February 18,1950, Serial No. 144,931

2 Claims. (Cl. Iii- 198) This invention relates to improvements vin anarticulated overhead door and, more particularly, to the hardware bywhich such door is supported and operated and by which the door may withease be elevated from a closed vertical position to an open overheadposition or lowered to said closed position from said open overheadposition, said hardware being of the type embodying a torsion springwhich counterbalances the weight of the overhead door.

It is an object of the present invention to provide improved hardwarefor supporting and operating an articulated overhead door of thecharacter described, which hardware is simple to install and adjust,rugged and durable in use, and more efcient in operation than hardwarepresently used for similar purposes.

Another object of the invention is to provide improved means forsupporting and varying the tension oi the torsion spring employed bysuch hardware, whereby the operation thereof is rendered highly efcient.

Details of the foregoing objects and of the invention, as well as otherobjects and advantages tion.

In the accompanying drawings, in which like reference numerals have beenused to indicate similar parts throughout, there is illustrated asuitable mechanical embodiment of the invention. The drawings, however,are for purposes of illustration only and arenot to be considered aslimiting the invention, the scope of which is to be determined entirelyby the scope of the appended claims.

In the drawings:

Fig. l is a vertical view illustrating one side of a garage doorway andshowing in dotted lines an articulated door in closed position, theimproved hardware being illustrated in assembled form as applied to thegarage doorway and door.

Fig. 2 is a fragmentary, foreshortened, vertical view taken on the line2--2 of Fig. 1 and illustrating a garage door and the supporting andoperating means therefor as viewed from the inside of the door.

Fig. 3 is a longitudinal, horizontal, sectional View showing details ofthe part of the hardware illustrated in Figs. l and 2 and shown on alarger scale than in said gures.

Fig. 4 is a sectional View taken on line 4-4 of Fig. 3, and

Fig. 5 is a sectional view taken on line 5--5 of Fig. 3.

- Referring to the drawings in detail, the numeral III generallyindicates part of the structure of a garage building provided with sidewalls and a front wall having a door opening I2 which is closed by adoor I4. The door I4, as illustrated, is of the type known in the art asan articulated overhead door. Such door4 is opened by moving the Vsamefrom the closed, vertical dotted-line position thereof shown in Fig. lto a horizontal overhead open position within the garage building. Thedoor is closed by moving it from the horizontal, overhead position tothe vertical position thereof.

The door is composed of a plurality of articulated sections connected byhinges IB and the various sections of the door are supported and guidedby tracks I-B disposed at each side of the door opening I2 and fastenedby suitable brackets to the door jamb. The track comprises verticalsections 20 and horizontal sections 22, the latter being supported fromthe ceiling or otherwise of the garage. The vertical sections 20 areconnected to the horizontal sections `22 by curved sections .24 of thetrack, whereby the track is substantially continuous from adjacent thedoor sill 24 of the garage to the outer ends of the horizontal sections22. As is evident from Fig. 2, the track I8, in cross section, isapproximately C-shaped for purposes of accommodating guide rollers 26which are rotatably supported within the various sections of the track.It is conventional practice to provide a roller 26 adjacent each hingeI6 at the side edges of the door I4 and the side edges of the bottomportion of the lowermost door section. The top of the door is pivotallyconnected at its side edges to arms 28, each of which support a pair ofrollers 2li.

Connected at its lower end to each track adjacent the junction of theupper end of the vertical section 20 thereof with the curved section 24is a vertically `disposed supporting member 30 which, in the embodimentshown herein, comprises an angle iron. One such member 3l) is secured toeach track by a plurality of bolts 32 which extend through one ange ofeach angle iron supporting member, as clearly shown in Fig. 1. The otherflange of each supporting member 30 may be attached by a plurality ofscrews 34 to the inner face of the door j amb 3B, as is clearly shown inFig. 2.

A brace 38, comprising an angle iron in the illustrated embodiment, issecured at one end to each track by bolts 40 adjacent the junction ofthe curved section 24 of the track with the horizontal section 22thereof. The other end of each brace 38 extends substantially to theupper end 3 of the supporting member 30 attached to each track. Abearing plate 42 is secured to the ends of each supporting member 36 andbrace 36 by a plurality of bolts 44, as shown in the various gures.

Each bearing plate is provided centrally thereof with an interruptedcylindrical flange 46, the flanges of the two bearing plates extendingtoward each other, as shown in Fig. 3. The nanges provide a seat for aball bearing assembly 48, the outer race of which preferably is presstted into the flange 46. As will be seen from Figs. 3 and 5particularly, there is disposed between the interrupted sections of eachflange 46 a plurality of fingers 55 which are initially formed so as tobe oifset lsomewhat from the plane of each bearing plate 42 in adirection opposite to the flanges 46. With the fingers so disposed, theball bearing assemblies 48 are inserted within the seat formed by theflange sections from the free ends thereof until the ball bearingassemblies 48 engage fingers 50. If desired, the free ends of theinterrupted sections of the flanges 46 may be made sufficiently longthat, after the bearing assemblies are mounted within the ange seats,the tip ends of the ange sections may be bent slightly over the edge ofthe outer race of each bearing assembly to hold said assemblies lockedwithin the flange seats and against fingers 50.

Mounted within the inner race of each ball bearing assembly 48 is abearing tube 52. Preferably, the tubes 52 are press-fitted within saidraces and flared at the outer ends thereof, as illustrated in Fig. 3.The bearing tubes extend outward from the ball bearing assemblies in thetwo bearing plates 42 and are directed toward each other, as also shownin Fig. 3. Extended between the bearing plates 42 and telescopicallyengaging the bearing tubes 52 at its opposite ends is a tubular shaft54. The fit between the shaft 54 and the bearing tubes 52 is preferablyclose so as to prevent any unnecessary play between said tubes andshaft. Surrounding each end of the shaft 54 is a flanged pulley orsheave 56 which may be formed in any suitable manner. In the embodimentillustrated herein, the sheaves 56 are formed from two sheet metalsections joined together to comprise a sheave having a hub 58 whichclosely engages the outer diameter of the shaft 54. tubes 52 havediametrically opposed and radially aligned openings which receive ananchor pin 60 for purposes of preventing rotation between said sheaves,shaft and bearing tubes.

The openings 62 in the bearing tubes 52 are preferably elongated axiallyand the openings 64 in shaft 54 are also preferably somewhat elongatedaxially to permit automatic self-adjustment of bearing tubes 52 relativeto the ends of the shaft 54-so as to compensate for normal installationinaccuracies as Well as shrinkage or expansion of the door jamb duringuse, without interfering with the operation of the hardware as it isintended to be used. Such self-adjustment is therefore permitted whilethe pins 66 prevent relative rotation between the various parts throughwhich the pins project in the assembled hardware.

Coiled within the base of each circular channel in each sheave 56 is ailexible strip 66 which is preferably made from flat stock. The outerend of each strip which is coiled about each sheave B is bent inward toprovide a securing end 68 disposed in a suitable slot l0 extendingradially inward from the base of the channel in each sheave The hubs 58,shaft 54, and bearing 4 56, as is clearly shown in Fig. 3. When thehardware is installed and the strips 6B are mounted in operativeposition, the ends 68 of each strip are inserted within the slots l0 andone or more convolutions of the strip are coiled about each sheave 56.The overlying convolutions ofthe coils of strips 66 will serve tomaintain the inturned end 68 thereof within the slots 'i6 providedtherefor. rThe other end of each strip 66 is. secured by any suitablemeans such as a pin 12 which projects outward from one edge of thelowermost section of the articulated door I4, as shown in Fig. 1, onepin projecting from each side edge of said section.

The sheaves 56, being both pinned to the shaft 54, will be rotatable inunison therewith. When the sheaves are rotated clockwise as viewed inFig. l, the strips 66 will be coiled progressively upon the sheaves andeffect a raising of the door I4 from its vertical closed positoin to itshorizontal, overhead, open position. In the latter position, the variousarticulated sections of the door will be disposed in the horizontalsections 22 of track and part of the curved sections 24 thereof.

The weight of the door is either largely or completely counterbalancedby means now to be described. Fixed to the leftnand bearing plate 42, asviewed in Fig. 3, is a bearing plate bracket 14. The bracket 14 may besecured to said bearing plate by any suitable means such as bolts or byproviding interengaging positioning means such as apertures T6 andprojections 'i8 thereon and spot welding or otherwise uniting the same.The bracket 'I4 comprises a plate 6d from which a plurality of arms 82extend perpendicularly, the outer ends of said arms being bent asillustrated in Fig. 3 for purposes of attachment to the bearing platebracket 'F4 to the bearing plate 42 in the manner described hereinabove.The plate 86 is provided centrally thereof with a bearing aperture 84.The larger end of a tapered spring sleeve 86 is rotatably supportedwithin said bearing aperture 84, said larger end 88 being preferablysubstantially cylindrical. The cylindrical end 88 is provided with aplurality of inwardly extending cut-outs 96, as clearly shown in Figs. 3and 4, and the portions of the outermost end of the cylindrical end 88of the spring sleeve 86 between the cut-outs 90 are bent outward toprovide radial locking flanges 92 which slidably engage one surface ofthe plate Si) of the bracket '14, as shown in Fig. 3.

A spider 94, comprising a centrally apertured plate 96 having aplurality of ears 98 bent perpendicularly thereto from the edgesthereof, is rotatably disposed in juxtaposition to the other surface ofthe plate from that engaged by locking flanges 92. The central apertureof plate 9.6 of spider 94 is similar in size to bearing aperture 84 ofplate 80 and said central aperture of plate 96 receives the cylindricalend 88 of spring sleeve 86. Extending inward from the perimeter of thecentral aperture i6@ of plate 96 are a plurality of locking dogs 102which extend into the bottom portions of the cut-outs 9e of springsleeve 86, as is clearly shown in Figs. 3 and 4. The locking dogs |02,being disposed within the bottoms of the cut-outs 96, thereby cooperatewith locking anges 92 of spring sleeve 86 to position the spring sleeve86 and spider 94 against axial movement relative to plate E0 of bearingplate bracket i4.

The plate 96 of spider 64 is also provided with a plurality of lockingapertures H34 which are spacedradially outward from the central aperture|00 of said plate, the radial distance of the center of each aperture|04 from the axis of rotation of the plate being equal to the radialdistance between said axis of rotation and the center of an aperture |06formed in plate 80 of bearing plate bracket "I4, as illustrated in Figs.2 and 4. Said apertures are for purposes of receiving a locking pin I03, the function of which is described hereinafter.

Fixed to the shaft 54 at a position a substantial distance from springsleeve 66 is a tapered anchor tube IIII. The tube |I0 is mountedrelative to spring sleeve 86 so that the tapers of the two extend towardeach other. Anchor tube I I0 is nonrotatably held to shaft 54 by anysuitable means such as a heavy cotter pin I I2 which extends throughsaid tube and shaft. Surrounding shaft 54 is a substantial length of aheavy coiled torsion spring II4, the inner diameter of which ispreferably greater than the smaller end of the sleeve 86 and tube I I0but less than the diameter of the larger end of said sleeve and tube.The spring I I4 is preferably of the type having abutting convolutionsand it is assembled so as to frictionally engage the outer surfaces ofsaid sleeve and tube as illustrated in Figs. 2 and 3. Such assembly canbe achieved by working the ends of the spring respectively onto saidsleeve and tube by turning the spring relative to each in the directionof the spiral of the spring. However, upon attempting to rotate thespring relative to said tube or sleeve in an opposite direction, thefriction between the engaged coils of the spring and the tube and sleevewill be increased in the same manner as a. spring clutch functions so asto effectively, frictionally connect said ends of the spring to saidtube and sleeve. The positioning of the spring H4 between the tube I|0and sleeve 86 and the nature of the spring serve to prevent appreciablemovement thereof longitudinally of shaft 54.

From the foregoing description, it will be seen that one end of thespring I I4 is frictionally connected to anchor tube I I0 which isnon-rotatably fixed to shaft 54. The sheaves 56 around which theflexible strips 66 are coiled are also Iboth nonrotatably fixed to theshaft 54. The opposite end of 4spring II4 is frictionally connected tospring sleeve 85. The spring sleeve 86, during the attachment of thehardware to the door and door jamb, is freely rotatable relative to theplate 60 of bearing plate bracket 14, said sleeve 86 being rotatableabout the axis of shaft 54. The spider 94 is keyed to the spring sleeve86 by means of dogs |02 and the-ears 98 of the spider 94 are eachprovided with an opening ||6 into which an end of a bar or piece of pipeof suitable size may be inserted for purposes of rotating said spider tovary the tension of the spring II4.

After the above described hardware has been connected to the door jamband other supporting surfaces of a garage or other building in which anoverhead door is to be installed, the lower ends of the flexible strips66 are attached respectively to the pins l2 fixed to the opposite sideedges of the lowermost section of the articulated door I4 as describedhereinabove. The hardware is then in condition for the spring I I 4 tobe placed under` tension for purposes of counterbalancing the weight ofthe door and also for supplying force largely or entirely capable ofraising the door from a closed vertical position to an overhead,substantial horizontal, raised position as referred to hereinabove. Suchtensioning of the spring II4 may be accomplished in several ways. Thatis, the spring may be initially tensioned While the door I4 is disposedin its vertical closed position, as illustrated in Fig. l, or the springmay be tensioned while the door is in its raised, overhead horizontalposition. Less initial winding of the spring will be required if thespring is tensioned while the door is in the latter position. Assuming,for example, that the door is in the latter position, the major portionof the flexible strips 66 will be coiled around the sheaves 56. Toinitially tension the spring under these circumstances, a bar or pieceof pipe such as referred to above may be inserted in one of the openingsIIB in the ears 08 of the spider 94 and the spider may be rotated in adirection to wind the spring |I4 and place it under tension. If there isnot sufficient space within the garage, for example, to permit a full360 of rotation of the spider 94 when the bar is inserted in one of theopenings IIB, the spider may be rotated as much as possible when the baris inserted in one of the openings I|6 and, after moving the spider apartial revolution, locking pin |08 is inserted through aperture |06 inbracket 'I4 and one of the locking apertures |04 in spider 94 which ismoved into alignment with said aperture |06. The locking pin will serveto hold the spider against rotation by the force of the spring I I4acting upon spring sleeve 86 to which the spider is keyed. The bar maythen be inserted in the opening II6 of another ear 98 of the spider andthe locking pin |08 is withdrawn from the aforementioned apertures topermit further rotation of the spider and spring sleeve 86 for purposesof further tensioning spring II4. Such tensioning of spring II4 will 'becontinued until the spring is placed under the desired amount of tensionfor purposes of enabling the spring to either partially or completelycounterbalance the Weight of the door during the raising of it from itsclosed to its open position.

After the spring I I4 has been placed under such desired amount oftension as aforesaid, the door may be lowered from its raised, overheadposition -to its vertical closed position and such lowering of the doorwill simultaneously rotate both sheaves 56 due to the unwinding of theflexible strips 66 therefrom. The rotation of the sheaves will alsorotate 4shaft 54 and anchor tube IIO in a direction to further windspring I4 and progressively place it under further tension. The springII 4 lwill be under its greatest tension so as to exert its greatesttorsional force when the door is fully extended into its closed,vertical position illustrated in Fig. 1. Also, the coils of ilexiblestrips 66 will be at their smallest external diameter under thesepositions, thereby presenting their shortest lever arms for applicationof the force of spring I I4.

Depending upon the amount of initial tension placed upon the spring I I4during the initial .setting of the hardware in operative condition asdescribed above, the door I4 will either be raised automatically fromits closed position to its open overhead position, or a certain amountof manual lifting of the door will be required to supplement thetorsional counterbalancing force supplied by the spring I I4. If thetorsional force of the spring |I4 is suflicient to automatically raisethe door, the door will then be held in its lower, vertical, closedposition by suitable lock means in accordance with customary practice.Upon releasing the bolt or bolts of the locking means, the door willthen automatically be raised by the hardware described above, throughthe torsional force of the spring II4, from its vertical closed positionto its overhead open position and be guided during such movement by thetracks which support the various sections of the articulated door.However, if the torsional force of the spring Hd is insufficient toautomatically raise the door upon releasing the locking means, thetorsional force of the spring will nevertheless function to extensivelycounterbalance the weight of the door so as to require only a minimumamount of manual force to supplement the force of the spring H4 forpurposes of raising the door.

It will be noted from Figs. 2 and 4 particularly that the locking pinIGS is of a character having a portion reduced in diameter adjacent oneend of the pin. The length of said reduced portion is substantiallyequal to the combined thickness of plate 536 of spider 94 and plate B0of bracket 74. The annular shoulders provided at the ends of saidreduced portion will serve to engage the outer surfaces of the plates 8Sand 96 and the force imparted to spider Se by spring I I4 will -act tomaintain portions of the walls of one of the locking apertures IS@ andapertures EUS in engagement with the reduced portion of the locking pin|08 in a manner to prevent separation of the pin Hi8 from saidapertures, as illustrated in Fig. 4.

If for any resason after use of the above described hardware thetorsional force supplied by spring II 4 becomes decreased below thedesired amount, said force may easily and readily be increased to theextent desired by rotating spider G4 in a direction to wind the springIIA further in the manner described above by means of a bar inserted inthe openings II of arms 98 of spider 94 after removing the locking pinIUS from the apertures in which it is disposed.

At the completion of the supplemental winding of the spring, the lockingpin H08 is replaced within the aforementioned aligned apertures asdescribed above for purposes of maintaining the spider 94 locked againstrotation relative to bearing plate bracket 'F4 during continued use ofthe hardw-are embodying the present invention.

It will thus be seen from the foregoing that the present inventionprovides hardware for purposes of counterbalancing the weight of anoverhead door so as to either largely facilitate the raising thereoffrom a closed to an overhead position or for completely andautomatically raising said door as aforesaid. The hardware isconstructed in a manner so as to be rugged and durable and capable oflong life, the details of the mechanism embodied in the hardwarepermitting easy and ready adjustment of the force supplied by thehardware, and such adjustment does not require special tools or askilled operator. The construction of the hardware is also such as torender the production thereof relatively inexpensive as compared withhardware of similar nature presently in use. The installation of suchhardware is simple and may be accomplished in relatively short time.'I'he hardware also includes means for Vpermitting automatic adjustmentto compensate for normal installation inaccuracies as well as expansionand contraction of the members of the door jamb to which the hardware isat tached, due to weather conditions.

While the invention has been illustrated and described in its preferredembodiment and has included certain details, it should be understoodthat the invention is not to be limited to the precise details hereinillustrated and described since the same may be carried out in otherways, falling within the scope of the invention as claimed.

I claim as my invention:

l. Means for adjustably supporting one end of a torsion spring forcounterbalancing an overhead door and comprising in combination, abracket arranged to be fixed relative to a door jamb and including aplate provided with a bearing aperture, a sleeve having one endrotatably supported within said aperture, said end having a cut-outextending inward therefrom and the outermost portion of said end beingradially flanged and engageable with one surface of said plate, theother end of said sleeve being attachable to one end of said torsionspring and operable to support and rotate it to vary the tensionthereof, a spider having an aperture receiving said sleeve and supportedthereby in parallel juxtaposition to the other surface of said plate,and a dog on said spider extending inward from the periphery of theaperture therein and disposed within the bottom of the cut-out in saidsleeve to key said spider and sleeve against relative rotation andcooperate with said radial flange to fix said sleeve againstlongitudinal movement relative to said bracket and spider.

2. In a counterbalancing mechanism for an articulated overhead doorhaving means rotatably supporting a shaft at the ends thereof and atorsion spring through which the shaft extends, the combinationtherewith of a bracket fixed relative to said .supporting means adjacentone end of the shaft and having a bearing aperture surrounding the shaftin spaced relation, a tapered sleeve surrounding said shaft `with itslarg-e end rotatably secured in said bea-ring aperture, said large endhaving a cut-out extending inwardly therefrom, a tapered tube spacedfrom said tapered sleeve longitudinally of said shaft and detachablyfixed against rotation relative to said shaft, the tapers of said sleeveand tube converging toward each other and said torsion spring beingdisposed ben tween and frictionally connected at its ends to the taperedexteriors of said sleeve and tube, a spider having an aperture receivingsaid sleeve and supported thereby between said spring and said bracket,a dog on said spider extending inwardly from the periphery of theaperture therein and disposed within the cut-out in said sleeve to keysaid spider and sleeve against relative r-otan tion, means on saidspider arranged to receive a tool operable to rotate said spider andsleeve relative to said bracket to vary the tension of said spring, andmeans engageable with said spider and bracket arranged to look saidspider and sleeve relative to said bracket.

DAVID M. ROBINSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 329,409 O-rrnsby Oct. 27, 18851,994,142 Madsen Mar. 12, i935 2,032,951 Pixley Mar. 3, 1936 2,097,242Robinson Oct. 26, 1937 2,294,360 Blodgett Sept. l, 1942

